An island in the Paracel chain in the South China Sea is captured in November 2016 in a Planet Labs handout photo received by Reuters.

The U.S. patrol was designed to challenge China's 'excessive maritime claims' in the area.

Vietnam has declared its support for freedom of navigation and peace and stability in the flashpoint East Sea, internationally known as the South China Sea, following a U.S. patrol designed to challenge China’s "excessive maritime claims" in the waters.

Foreign ministry spokesperson Le Thi Thu Hang said at a regular press briefing on Thursday that Vietnam stands by its consistent viewpoint that all countries have the right to freedom of navigation in the territory in accordance with international law.

Hang said Vietnam holds enough historical evidence and legal foundations to assert its sovereignty over the islands.

“Any activity carried out in the area without Vietnam’s permission is illegal and invalid,” she said.

Vietnam continues to call on countries to contribute constructively and positively to maintaining peace, stability and law in the East Sea, Hang said.

Hang made the statement two days after a U.S. Navy destroyer sailed near the Paracels in a move that U.S. officials described as a challenge to “excessive maritime claims” by Beijing.

The Chafee, a guided-missile destroyer, carried out regular maneuvers near the archipelago.

Three U.S. officials told Reuters that the operation was the latest attempt to counter what Washington sees as Beijing’s efforts to limit freedom of navigation in the strategic waters.

The Pentagon did not comment directly on the operation, but said the U.S. carried out regular freedom-of-navigation operations and would continue to do so, Reuters said.